The present invention relates generally to the conversion of bio-mass and bio-mass waste streams via the process of bio-gasification and, more specifically, to the conversion of bio-mass and bio-mass waste streams to produce higher order chemicals such as urea.
Although the conversion of biomass and biomass waste streams via the process of bio-gasification (syngas) to produce usable products has been accomplished to varying degrees of effectiveness and efficiency in the past, the gasification of bio-mass to produce urea is yet untapped. The main technical barriers cited by the U.S. Department of Energy to utilizing bio-mass-based syngas to produce higher order chemicals such as urea are: (1) feed process and handling; (2) gasification/conversion; (3) gas cleanup and catalytic conditioning; (4) syngas utilization; (5) process integration; and (6) process control, sensors, and optimization.
Prior art gasification systems using bio-mass as a feedstock stop at the formation of syngas. Because this syngas is of low quality, it cannot be directly used to produce higher order chemicals such as urea. Rather, the syngas is used to power generators or mixed with a natural gas stream being converted to urea (see technical barrier 3 above). In addition, the prior art requires large production units or large-scale plants. Because of the high volume of production required by these plants, the input material must be run through sequential processing units before the syngas can be converted to ammonia. Because of the size of the plants, the plants tend to be located far away from all of the ready and available sources of bio-mass feedstock, thereby increasing transportation costs or—in the case of remote rural or geographically challenging areas—making it extremely difficult if not economically infeasible to locate a plant or transport the bio-mass to the plant. This bio-mass feedstock, which tends to be stored in fields prior to it being transported to the plant and processed, is usually dirty, of low storage density, and difficult to handle (see technical barrier 1). Furthermore, the bio-mass feedstock varies considerably in its processing characteristics both between and within types of bio-mass. This variation makes it difficult for plants to control, much less optimize, the conversion process and maintain a high level of conversion efficiency (see technical barriers 2 & 4-6 above).